Pressing machines of the kind which operate on a work piece inserted into the machine by hand are inherently a source of injury to the operator due to the possibility of the operator accidentally inserting his hands or fingers into the working area of the machine. The working area in a typical pressing machine is the area between a fixed horizontal bed and a vertically movable ram which descends during a pressing operation to shape a work piece such as metal sheet against the bed. In many operations the work piece is manually grasped along one edge by the operator and is placed on the bed while the ram is up. The operator may release the work piece at this point or he may continue to hold the edge of the work piece if the edge lies outside the path of travel of the ram. In either case there is the possibility that the operator's hands or fingers can accidentally be caught between the ram and the work piece or the bed as the shaping operation is carried out.
It is known to provide guards for pressing machines of this type which block access to the work area and thereby prevent entry of both work piece and the operator's hands into the work area. These guards, often constructed in the form of a cage-like structure must be removed in part or in whole before a pressing operation can be carried out, and they therefore do not prevent entry of the operator's hands or fingers into the work area.
The present invention provides a guard for this type of machine which is constructed and arranged to serve as a stop to be engaged by the operator's arms as he extends his arms toward the machine's work area. While not obstructing the passage of the work piece into the work area. The principal element of the guard is a horizontal bar extending along the length of the work area and disposed between the latter and the operator at an elevation above the bed of the machine and somewhat above waist height. In this position there is sufficient space below the bar to permit the work piece in the hands of the operator to pass under the bar and into the work area. As the work piece approaches the work area the operator's forearms approach the bar and contact the same before his hands enter the work area. By previously adjusting the elevation of the bar and its proximity to the work area it is possible to compensate for differences in the "reach" of the operator resulting from variations in the height and arm length of different operators.
In the preferred construction the guard includes the horizontal guard bar, an arm fixed at each end of the bar extending toward the machine, two fixed upright support posts spaced apart a distance equal to the distance between the arms, and connecting means between the inner ends of the arms and the upper ends of the posts for effecting adjustment of bar in a vertical plane parallel to the plane of the posts and in a horizontal plane toward and away from the machine. In this arrangment the support posts can be located quite close to the machine so as not to constitute an obstruction. In addition the arms at the ends of the bar prevent accidental insertion of a person's hands into the work area from the sides of the machine.